Influence of substituents in the pyrazole pre-ligands on their reaction products with (Phen)Pd(OAc)2.

[Display omitted] The unique palladium(ii) complexes, namely, (Phen)Pd((CF 3) 2 pz) 2 , (Phen)Pd(MeCF 3 pz) 2 , and [(Phen)Pd 2 (μ-dmpz) 2 (dmpz)(Hdmpz)](OAc) 2 H, where (CF 3) 2 pzH is 3,5-bis(trifluoro methyl) pyrazole, MeCF3pzH is 3-methyl-5-trifluoro methylpyrazole, Hdmpz is 3,5-dimethyl- pyrazole, Phen is 1,10-phenanthroline, have been obtained by the reactions of (Phen)Pd(OAc) 2 with the corresponding free NH -pyrazoles. According to the X-ray data, in the mononuclear pyrazolate complexes the Pdii atom has a square planar environment of nitrogen atoms of phenanthroline and two monodentate-bound pyrazolate anions. The binuclear pyrazolate-bridged complex is additionally stabilized by intramolecular hydrogen bonding of the terminal dmpz anion and Hdmpz. [ABSTRACT FROM AUTHOR]